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#ifndef main_timer_avr_h
#define main_timer_avr_h
/* main_timer.avr.h */
/* io - Input & Output with Artificial Intelligence (ai) support on AVR. {{{
 *
 * Copyright (C) 2008 Dufour J�r�my
 *
 * APBTeam:
 *        Web: http://apbteam.org/
 *      Email: team AT apbteam DOT org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * }}} */

/**
 * @file Main timer module.
 * Main timer module is used for the main loop of the io board to ensure it is
 * executed only to the defined loop time (at the maximum). It uses the
 * timer/counter 0 of the AVR.
 */

/**
 * Initialize the main timer to 4.444 ms.
 */
static inline void
main_timer_init (void)
{
    /* Fov = F_io / (prescaler * (TOP + 1))
     * TOP = 0xff
     * prescaler = 256
     * Tov = 1 / Fov = 4.444 ms */
    TCCR0 = regv (FOC0, WGM00, COM01, COM0, WGM01, CS02, CS01, CS00,
                     0,     0,     0,    0,     0,    1,    1,    0);
}

/**
 * Wait until the main timer overflows.
 */
static inline void
main_timer_wait (void)
{
    /* Loop until an overflow of the timer occurs */
    while (!(TIFR & _BV (TOV0)))
	;
    /* Write 1 to clear */
    TIFR = _BV (TOV0);
}

#endif /* main_timer_avr_h */